Sewing machine



March 31, 1953 Filed March 51. 1949 R. CASAS ROBERT ETAL 2,633,092

SEWING MACHINE I 4 Sheets-Sheet 1 4 an m a g:

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March 31, 1953 R. CASAS ROBERT ETAL 2,633,092.

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SEWING mum:- mea um :51. 1949 4 Sheets-Sheet s March 31, 1953 R. cAsAs ROBERT ETAL SEWING MACHINE Filed Mrch 51, 1949 4 Sheets-Shet 4 Patented Mar. 31, 1953 SEWING MACHINE Ramon Casas Robert and Jean Court, Geneva,

Switzerland, assignors to Mefina S. A., Binningen, Switzerland, a corporation of Switzerland Application March 31, 1949, Serial No. 84,612 In Switzerland January 14, 1949 main shaft driving, on the one hand, the needlebar and the thread-puller by means of transmission elements such as cranks and connecting rods, and, on the other hand, the feeding device and the shuttle by means of connecting rods, transmission shafts and gears. Now, it is very difilcult to eliminate entirely all slack in transmissions including connecting rods and gears, so that there occur variations in the relative positions of the feeder, of the needle and of the shuttle hook, which are the cause of irregularities in the seam, or even of misses in the case of excessive wear, of the transmission elements.

It is also well known that transmission by means of gears and connecting rods become noisy in the course of time, due to wear, which is the cause of an unnecessary strain for the operator.

Certain manufacturers have endeavoured to reduce the above mentioned drawbacks by partly eliminating the slack in the transmission connecting the main shaft to the shuttle. For this purpose, they have fitted their sewing machines with a, belt provided with holes or with clamps, running on two sprocket wheels fastened respectively to the main shaft and to a transmission shaft mechanically connected to the shuttle. However, with these machines, there is always slack in the transmission connecting the main shaft to the driving member for the feeder, and slack in the shuttle movement drive, these being produced by means of connecting rods or gears. The resultis that the stitches of a seam are not all regular.

The present invention relates to a sewing machine including a main shaft actuating a needlebar, a thread-puller, a feeder actuated by a revolving driving element and a rotary shuttle. This machineavoids the above mentioned drawback since the main shaft is connected to the revolving shuttle and to the revolving driving element for the feeder by a single flexible connecting member running on four sprocket wheels, of which three are fastened respectively to the main shaft, to the revolving shuttle and to the revolving driving element of an actuating mechanism for the conveyer.

The attached drawing shows diagrammatically and by way of example a form of construction of the sewing machine. Figs. 1 and 2 are side views, with parts cut away from the free arm and from the needlecarrying arm of the machine, the column bearin these arms being partly shown.

9 Claims. (Cl. 112-220) Fig. 3 is a top view of the free arm, some parts of its walls and of the mechanisms therein enclosed being cut away in order to expose the flexible connecting member.

Fig. 4 is a perspective view of the mechanisms arranged in the free arm and of their connection to the main shaft of the machine.

Fig. 5 is a detail view.

Fig. 6 is a perspective view of a clamp and of its fastening device, ready to be fixed to a belt.

As shown in the attached drawing, the sewing machine includes a free arm I and a needlecarrying arm 2 supported by a column 3. These three parts form together a casing containing and safeguarding the various mechanisms of the sewing machine, of which only those necessary for a proper understanding of the invention will be described here.

The needle-carrying arm 2 is traversed over the greatest part of its length by a main shaft P, carrying at one of its ends a fly-wheel 4 and a driving pulley 5. This shaft P revolves in bearings 6 (of which only one is visible on Fig. 1) fastened to the casing of the machine.

The free arm contains the actuating mechanisms for the feeder and for the shuttle elements. These mechanisms are described in U. S.

. applications Serial Nos. 84,608; 84,610; 84,611,

and will be described here only for the purpose of understanding their operation.

The feeder I (Fig. 4) is fastened to a support 8 carried by two levers 9 and [0 of which one, 9, is rigid and rocks around a vertical shaft ll, while the second, I0, is elastic and rocks around a horizontal shaft l2.

The lever 9 is provided with an extension 9a angularly adjustable relative to lever 9 by means of screw '0.

The rocking movements of these two levers 9 and [0 are controlled by a single cam I3. Indeed, the lever 9 carries an actuating element l4 provided with a cam follower surface l6. Element I4 is fixed to several rods axially slidably mounted on the end of lever extension 9a and subjected to the action of a spring [5 tending to keep surface H5 in contact with the profile of the cam l3. In addition, this actuating element l4 carries a part I! slidably engaged in a slot in a guide l8 which is mounted so that it will not reciprocate with part I1. A guide i8 is fixed on the lower end of a rotatable shaft 11 so that the angle of inclination of the slot therein in relation to a plane perpendicular to the driving axle ll! of the cam 13 can be chosen and fixed at will by adjusting elements described in copending application Serial No. 84,608.

If the slot in guide I8 is perpendicular to the axis of shaft I9, no oscillation of lever 9 about shaft II will take place. On the other hand, however, upon inclining the slot in guide I8 by rotating the latter, the pin I'I will be moved axially of shaft I9 as it reciprocates perpendicularly to the axis of shaft I9 and this will cause lever 9 to oscillate about shaft II. The degree of oscillation of lever 9 will depend upon the angle of the slot in guide 18 relative to the axis of shaft I9.

Finally, the arm 9 carries a shaft '23 sliding in guides 24 arranged in the support 8. The lever I carries a finger 2I urged by a spring 2-2 in contact with the profile of the cam I3, while its end is hinged to the support 8 by means of an axle 26 revolving in a bearing arranged in the support 8.

By examining the Fig. 4 of the "attached drawing, it will be seen immediately that the lever 9 is actuated in a rocking movement around its vertical axle II, the extent :of which is 'a function of the angle of inclination of the slot in guide I8, while the lever I 0 is actuated :in a rocking movement, of constant extent, around its horizontal axle I2. Due to the flexibility of this lever [0 its end is capable of following the :rocking movement of the support 8 in the horizontal plane, imparted by the lever 9, and, in addition, the lever 9 can follow freely the rocking movement in the vertical plane, imparted by the lever I9, due to the fact that, on the one hand,'the end of this lever is hinged to the support 8 by means of the axle 26 and, on the other hand, that this support slides along the axle 23 carried by the end of the lever 9.

Thus, the feeder is simultaneously actuated in synchronized horizontal and vertical rocking movements, so that it runs along a closed path.

The revolving shuttle includes a revolving cup 21 fastened to a sleeve 28 (Fig. 2) revolving freely on an axle I4 rigidly fastened in the casing of the free arm I, and a bobbin 29 (Figs. 3 and 4) carried by a support 30 kept in a fixed angular position, by mobile stops 3| and 32 alternately acting in conjunction with stops 33, 34 fastened to the said support 30. The mobile stops 3I and 32 are carried by one of the arms of a lever 36, of which the other arm is kept, by an elastic action, in contact with the profile of a cam 35 carried by the shaft I9. This lever 36 is hinged to the frame of the machine by means of a "spring blade 31 fixed, on the one hand, by fastening organs 38 to a part 40 fastened to the frame of the machine, and, on the other hand, by fastening organs 39 to a portion of the lever 36 As shown on the drawing (Figs. 2, 3 and 4) the main shaft he riving shaft I9 and the sleeve 28 carrying cup 21 are mechanically connected between themselves by a single flexible connecting element 4| running on four sprocket wheels 42,43, 44 and 45.

Three of these chain wheels are fastened respectively to the main shaft P, to the driving shaft I9 and to the sleeve 28 carrying the cup 27, while the fourth revolves freely on an axle 46 (Fig. mounted on a rocking support 48. The latter pivots on an axle 49 rigidly fastened to the frame of the machine and includes a bearing 59 in which revolves the driving shaft I9, and two arms 60 carrying the axle 46 on which revolves freely the sprocket wheel 45.

The sprocket wheels 42 and 43 are of the same diameter, since the revolving speeds of the main shaft and of the driving shaft are the same. On the contrary, the cup 21 having to revolve at twice the speed of the main shaft, the chain wheel 44 has a diameter equal to the .radius of the chain wheel 42.

The flexible connecting element consists of a belt fitted with equidistant lugs 5|, engaging in recesses 52 in the periphery of the sprocket wheels. It is obvious that flexible connecting elements of other kind could be used, such as perforated belts, for instance, in which case the sprocket wheels would then be fitted with lugs acting in conjunction with the belt perforations.

A controlling device 6!, consisting of a screw threadedly mounted in a part of the frame and of which the end acts on the rocking support 48, makes it possible to tighten to a greater or a lesser degree the belt and to obtain a smooth and silent running of the machine. Indeed, no slack at all should exist in the described transmission, so that absolute synchronism of the movements of the needle A, of the conveyer I and of the cup 21 is automatically ensured, which enables the formation of a seam of perfect regularity.

In order to permit the movement of the sprocket wheels '43 and 45 in relation to the sprocket wheel 42, necessary to the obtention of the desired belt tension, the sprocket wheel 42 has a Width e greater than the width b of the belt.

The driving shaft I9 being carried by the rocking support 48, the displacements of the latter, during the adjustment of the belt tension, provoke displacements of the cam I3 perpendicular to the shaft I9. The result is that the part I1 is displaced in the guide I8. This displacement has no effect at all on the synchronism of the movements of the feeder 7. On the contrary, it is necessary to design the guide I8 with a length sufficient to allow such displacements of the middle position of the part I? in the guide I8. As described in our copending application Serial No. 84,610, now Patent No. 2,578,225, dated December '11, 1951, the middle position of the conveyer in relation to the needle A can be chosen by angular displacement of the extension 9a of the lever 9 relative to the lever. The relative position of the extension 9a of the lever 9 can be fixed by means of a screw 12. However, in the form of the device shown on the attached drawing, the middle position of the part I! can be fixed independently from the position occupied by the driving shaft I9. For this purpose, the cam follower surface I6 is provided on a removable small plate 62 having a slot 63. This small plate is mounted in a recess 64 in the actuating element I4 and is clamped in this housing by means of a screw 65 traversing the slot 63 and of a flange 66, engaged under the head of this screw 65. Thus, by changing the position of this small plate 62, it is possible after having adjusted the desired belt tension, of bringing back the middle position of the part I! to the center of the slot of the guide IS.

The angular position of this guide I8 is chosen and fixed as described in detail in copending application Serial No. 84,608, by acting on the lever pivoting on the bearing 6 of the main shaft P, and of which one of the arms 1 emerges from the casing of the machine through a port I5 made in said casing. The other arm g cooperates with a cam follower I6 fastened to shaft I1 carrying the small plate.

guide It! and subjected to the action of a spring 18 tending to keep the follower 16 in contact with the arm g.

Finally, the described flexible connection linking the main shaft to the driving shaft and to the shuttles sleeve makes it possible, not only to obtain a silent working of the machine as well as the obtention of a machine capable of doing rectilinear seams which are absolutely regular, from their length point of view as well as that from their tension, but also to incline the axle of the shuttle in relation to the vertical in a plane perpendicular to the advancement displacement of the feeder l, which, as described in our copending application Serial No. 84,611, makes it possible to obtain a very great regularity of the stitches of a zig-zag seam or of a decorative motive.

Indeed, as shown on the drawing, such an inclination a of the axle M complicates in no way at all the transmission. It is suflicient, in fact, to incline the axle 46 of the sprocket wheel 45 by an angle 0, equal to the angle a in relation to the horizontal, and to provide the two sprocket wheels 43 and M with flanges Bl.

Lastly, with a view to prohibit any possibility, in case of insufficient tension of the belt, of a jump of the lugs 5i jumping from one recess 52 into another, which would disturb the timing of the three revolving elements connected by the flexible connecting element, guards 68 partly surround the four sprocket wheels. The distance d between the internal wall of a guard 68 and the external face of the belt 4| is smaller than the height h of the lugs 5|. The latter consist of semi-cylindric elements 69 (Fig. 6) provided with spikes 10, and of a small plate H having openings 12, intended to receive the spikes 10 and to enable their riveting, the belt being clasped between the edges 13 of the half-cylinder and the The belt consists preferably of a woven ribbon and the spikes 10 have sharp ends. It is thus possible to set in place the half-cylinder on the belt without provoking rents, the spikes 10 being driven between the fibers of the woven ribbon. If care is taken to drill holes 12 of circular transversal section, there is practically no risk at all of cutting off fibers when riveting the spikes to the small plate H.

We claim:

1. A sewing machine comprising a main shaft, a needle-bar and a thread-puller driven by said main shaft, a feeder, a revolving driving element for said feeder, a revolving shuttle, a sprocket wheel fixed to the main shaft, a second sprocket wheel fixed to the feeder driving element, a third sprocket wheel fixed to the revolving shuttle, a fourth idler sprocket wheel mounted adjacent said second sprocket wheel, and a single flexible endless driving element running on said four sprocket wheels, said feed driving element and said idler sprocket being interposed between said main shaft and said shuttle in the path of said endless driving element, and the axes of the feed driving element and said idler sprocket being in planes substantially perpendicular to the axis of the main shaft and with the main shaft and the shuttle spaced transversely from the axes of said feed driving element and said idler sprocket.

2. A sewing machine as claimed in claim 1 and comprising a rocking support, an axle for said support disposed parallel with the rotation axis of said revolving element driving said feeder, the second and fourth of said sprocket wheels being carried by said rocking support and means for urging said rocking support against the tension of said flexible element.

3. A sewing machine as claimed in claim 1 and comprising a rocking support, a shaft bearing the second sprocket wheel and said revolving element driving the feeder, said shaft revolving freely in a bearing provided in said rocking support, an axle mounted on said rocking support, the fourth sprocket Wheel revolving loosely on said axle, an axle for said rocking support mounted on a fixed part of said machine and disposed parallel with the rotation axis of said shaft bearing said second sprocket wheel and said revolving element driving said feeder and means acting on said rocking support for adjusting the tension of said flexible connecting element. 3

4. A sewing machine as claimed in claim 1, and comprising a rocking support, a shaft bearing the second sprocket wheel and said revolving element driving the feeder, said shaft revolving freely in a bearing provided in said rocking support, a second revolving element fastened to said shaft, a rocking lever driven by said second revolving element against an elastic action, two stops fastened to said rocking lever, two sprongs fastened to a bobbin support of said shuttle and extending radially with respect to said shuttle, said stops cooperating alternately with each of said sprongs so as to hold said bobbin support in a fixed angular position, an axle mounted on said rocking support, the fourth sprocket wheel revolving loosely on said axle, an axle for said rocking support mounted on a fixed part of said machine and disposed parallel with the rotation axis of said shaft bearing said second sprocket wheel and said revolving element driving said feeder, and means acting on said rocking support for adjusting the tension of said flexible connecting element.

5. A sewing machine as claimed in claim 1 and comprising a rocking support, a shaft bearing the second sprocket wheel and said revolving element driving the feeder, said shaft revolving freely in a bearing provided in said rocking support, an axle mounted on said rocking support, the fourth sprocket wheel revolving loosely on said axle, an axle for said rocking support mounted on a fixed part of said machine and disposed parallel with the rotation axis of said shaft bearing said second sprocket wheel and said revolving element driving said feeder, means acting on said rocking support for adjusting the tension of said flexible connecting element, an actuating mechanism linking mechanically said feeder to said revolving element, and. an adjusting device provided on said actuating mechanism for selecting and fixing the middle position of said feeder independently of the position occupied by said shaft carried by said rocking support.

6. A sewing machine as claimed in claim 1 and comprising a rocking support, a shaft bearing the second sprocket wheel and said revolving element driving the feeder, said shaft revolving freely in a bearing provided in said rocking support, an axle mounted on said rocking support, the fourth sprocket wheel revolving loosely on said axle, an axle for said rocking support mounted on a fixed part of said machine and disposed parallel with the rotation axis of said shaft bearing said second sprocket wheel and said revolving element driving said feeder, means acting on said rocking support for adjusting the tension of said flexible connecting element, a cam carried by said shaft, an actuating mechanism linking said feeder to said cam, a cam follower fastened to said actuating mechanism and cooperating with said cam, and means to adjust the position of said cam follower with respect to a lever of said actuating mechanism, which lever drives said feeder in a horizontal to and fro movement.

7. A sewing machine as claimed in claim 6, in which said actuating mechanism comprises a second lever which is elastic, a finger fastened to said second lever and cooperating with said cam under an elastic action, said lever imparting a vertical to and fro movement to said feeder.

8. A sewing machine as claimed in claim 1 and wherein the axis of rotation of said shuttle is inclined in relation to the vertical in a plane perpendicular to the advancement stroke of said feeder.

9. A sewing machine as claimed in claim 1 and comprising a rocking support, an axle for said support disposed parallel with the rotation axis of said revolving element driving said feeder, a shaft driving said revolving element and bearing the second sprocket wheel, a bearing in said rocking support, said shaft revolving in said bearing, the axis of rotation of said shuttle being inclined in relation to the vertical in a plane perpendicular to the advancement stroke of said feeder, an axle carried by said rocking support and bearme said fourth sprocket wheel, said axle being inclined in relation to the horizontal in a vertical plane parallel with said shaft, and means acting on said rocking support for adjusting the tension of said flexible connecting element.

RAMON CASAS ROBERT. JEAN COURT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 572,538 Goddu Dec. 8, 1896 842,934 Bolton et a1 Feb. 5, 1907 

